Role of 5-HT1A in the nucleus of the solitary tract in the regulation of swallowing activities evoked by electroacupuncture in anesthetized rats

Somatic stimulation therapy, such as electroacupuncture (EA), has been widely applied in the clinic to treat dysphagia. However, its underlying mechanism has remained unknown. In the present study, the effect of EA at acupoints Fengfu (DU16) and Lianquan (RN23) on swallowing activities and the involvement of 5-HT1A in the nucleus of the solitary tract (NTS) were examined in anesthetized rats. EA at DU16 and RN23 significantly evoked myoelectric activity of the mylohyoid muscle, which was attenuated by injection of 10 nmol 5-HT1A antagonist (WAY-100635) into the NTS. Meanwhile, 5-HT1A expression in the NTS increased following EA. The results suggested that EA at DU16 and RN23 promotes swallowing activity, and 5-HT1A in the NTS may play an important role in the excitatory effects.